By David Crystal

New from Cambridge University Press!

By Peter Mark Roget

This book "supplies a vocabulary of English words and idiomatic phrases 'arranged … according to the ideas which they express'. The thesaurus, continually expanded and updated, has always remained in print, but this reissued first edition shows the impressive breadth of Roget's own knowledge and interests."

Book announcement on Linguist: http://linguistlist.org/issues/12/12-2361.html

INTRODUCTIONThis book explores the structure and interaction of bootstrapping mechanisms available to the language-learning child, focusing on the child's sensitivity to certain properties of the input. The 'bootstrapping' problem is one of the most fundamental issues in the study of child language: to acquire language a child must parse the signal, but parsing the signal requires knowledge of the language. Importantly, the editors have chosen to take an interdisciplinary and cross-linguistic approach to this topic.

The two volumes of 'Approaches to bootstrapping' together consist of five separate parts. The first two parts focus on the nature of the input and its cues to lexical and syntactic knowledge. The third part concerns early language production, and the role of prosodic and morphosyntactic knowledge. Part IV addresses neurophysiological aspects of language acquisition, and part V concludes with some additional perspectives on the issues raised.

In the following review, a selected number of articles from 'Approaches to Bootstrapping' will be discussed. This selection is based on the interests of the reviewer, and does not reflect the merit of these articles in comparison with others.

SYNOPSIS Part I deals with early word learning and its prerequisites. In 'Bootstrapping from the signal: Some further directions', Jusczyk gives an excellent and useful overview of the author's important contribution to the field. Previously published and unpublished data are provided concerning infants' word segmentation abilities. The author reports mainly on studies that use versions of the Headturn Preference Procedure (Jusczyk and Aslin 1995). These studies have shown that English-learning 7.5-month-olds have some ability to segment words in fluent speech. 7.5-Month-old infants (but not 6-month-olds) seem to have acquired crucial information about the sound organisation of their native language, including word stress, allophonic cues, phonotactic constraints and distributional regularities. Infants seem to show a preference for bisyllabic words with a WS pattern as initial (first-pass) strategy, consistent with the Metrical Segmentation Strategy (MSS) as proposed by Cutler (Cutler, 1990; 1994), identifying the occurrence of strong syllables with the onsets of new words in fluent speech. However, infants do not detect familiarised WS words (guitar, surprise), which constitutes evidence for use of distributional cues to determine where the word is likely to end. However, it is argued that additional information based on allophonic cues or phonotactic sequences may override a segmentation strategy based purely on stress cues.

Jusczyk proposes that children use strategies that allow them to 'divide and conquer the input': carving the input up into word-sized units provides the child with opportunities for observing regularities in allophonic and phonotactic properties which occur at the onsets and offsets of these units. The second part of this article addresses the relationship between word segmentation and syntactic organisation. From previous work it has become clear that infants are sensitive to prosodic organisation in clauses and phrases (Gerken et al., 1994; Jusczyk et al, 1992). The author suggests that infants' developing word segmentation abilities may play a role in this process by enabling the learner to track the distribution of grammatical morphemes within the boundaries of prosodic phrases. However, infants draw on a variety of sources of information - conceptual and linguistic - to learn about the syntactic organisation of the language.

Although this article is one of the most important ones in the book, and fits in well with the overall aim of the volumes, it does not contain much new or unpublished data. The articles cited are not very recent (the latest being (Jusczyk et al., 1999)) and a more extensive overview of Jusczyk's work can be found in his book 'the discovery of spoken language' (Jusczyk, 1997). Some of the more problematic issues that are not dealt with concern the methodology and the precise nature of the Headturn Preference Procedure. Thus, it is unclear how to determine whether longer looking times represent a preference for new stimuli or a preference for familiar stimuli. Also, the difference between discrimination on the one hand and preference on the other is not discussed in any detail.

Furthermore, overview articles like this can make it difficult to evaluate results since no specific data are given. For example, the author confines himself to stating "the overall performance by the 7.5-month-olds suggests that infants do have some capacity to deal with interference from competing voices".

Echols' 'Contributions of Prosody to Infants' Segmentation and Representation of Speech' is very clear and well-structured article, which further addresses the origin of word-level segmentation, as well as the availability and use of prosodic cues such as perceptually salient syllables and rhythm. Experimental findings suggest that the salience of both stressed and final syllables may derive from acoustic features used to prosodically highlight these syllables. Furthermore, both types of syllable are attended to and represented more precisely by 9-month-old infants. Thus, these perceptually salient syllables may serve as prosodic cues for word-segmentation, although the relative roles of these cues may change with development.

Fisher & Church's article links acquisition to perceptual learning and memory processes. The authors argue that the Perceptual Representations Systems (PRS) framework makes learning an integral part of speech perception: long-term auditory priming as phenomenon of implicit rather than explicit memory, is mediated by a learning mechanism that could contribute to the creation of a long-term store of word-sounds in children, as well as to the life-long adaptability of speech processing to context.

Fernald, McRoberts and Swingley focus on early word recognition, stressing the graded nature of developmental changes. Increased speed, accuracy and efficiency of spoken word recognition in the second year of life are argued to not only reflect changes in cognitive capabilities (not specific to language processing), but also to reflect changes in infants' lexical representations. The authors provide evidence from eye-tracking studies that suggest that infants have some ability to process speech incrementally, providing evidence against the assumption that early lexical representations are holistic or phonetically underspecified. It is not entirely clear however what is meant by 'holistic' or 'phonetically specified', and whether these two concepts are in fact opposed to one another.

Part II focuses on input cues to syntactic knowledge. In the first article, Gerken provides an overview of recent research on the nature of the input and early acquisition of syntax, arguing for a bridge between the two. She makes the important point that "if one type of grammatical representation of a particular utterance is extractable from the signal and another representation for the same utterance is not, the extractable representation should be treated as a priori more plausible".

The remaining articles address possible prosodic cues to the acquisition of syntax. For instance, Höhle, Weissenborn, Schmitz and Ischebeck found prosodic differences between sentences involving head-complement constructions as compared to head-modifier constructions.

Penner, Wymann and Weissenborn address the well-known discrepancy between the child's perceptive capacity and speech production when they discuss the prosody-lexicon interface. They propose that the child makes use of a robust algorithm for prosodic bootstrapping, the 'Rhythmic Activation Principle' or RAP. This will enable the child to set the head directionality parameter, by mapping the pattern of relative prominence in the phonological phrase onto the corresponding complement-head configurations in the syntax. The authors show that this algorithm is successfully applied by normally developing children as well as language-impaired children. The production lag follows from the fact that the child resorts to an underspecified representation of the phonological phrase, due to a conservative learning principle. The difference between the two groups is explained by stating that underspecified representations become persistent in language-impaired children.

Part III addresses interactions of prosodic and morphosyntactic knowledge in early language production.

Demuth argues for a constraint-based approach to acquisition. She also discusses implications of her approach for the identification of children at risk of language delay.

Freitas, Miguel and Hub Faria show that acquisition of syllabic structures, like codas in European Portuguese, might depend on the grammatical features encoded by them. Thus, interaction between prosody and morphology may have consequences for the order of acquisition.

In part IV, neurophysiological aspects of language acquisition are addressed. In the first article, Morfese provides an excellent overview of studies using ERP (event-related potential) procedures to study infant and toddler word acquisition. Interestingly, it describes studies investigating speech perception and phonology, which is a well-covered area in this type of research, as well as studies on early word acquisition and word discrimination.

As the two remaining articles show a considerable overlap with this review article, their inclusion seems unnecessary.

Finally, Part V groups together studies on additional perspectives to language acquisition, addressing questions of methodology, the nature of linguistic primitives, and the development of bird song as compared to human language acquisition.

Plunkett's excellent article on interactionist approaches reviews contributions of behavioural, neuropsychological and computational studies to the field of acquisition, focusing on speech perception, word recognition and the acquisition of inflectional morphology. He makes a case for a multi-disciplinary approach to language acquisition, stressing that linguistic development should be seen as 'the interaction of powerful general learning mechanisms with a richly structured environment that provides the necessary ingredients for the emergence of mature linguistic representations'.

GENERAL COMMENTSIn general, the selected articles reflect experimental psycholinguistic work, with little reference to current generative theories such as Optimality Theory. Still, 'Approaches to Bootstrapping' presents an excellent (if not state-of-the-art) interdisciplinary overview of recent developments in first language acquisition research. It is regrettable that it has taken such a long time to publish this important book, but it is undoubtedly a valuable contribution to the field. It will be useful as a reference book for scholars from a wide range of interests within psychology and linguistics. It is not introductory, and as such not suitable as a textbook.

ABOUT THE REVIEWER:
ABOUT THE REVIEWER I am in the first year of my PhD studies at Utrecht University, investigating the acquisition of morpho- phonological alternations by Dutch-speaking children. My interests are the development of phonological representations for perception and production and the phonology-morphology interface.